RI, MA EHS Pest Control Blog

It's true: Rodents Will Chew on Your Car's Wires

Chew on this. Your warm car engine may also have a warm rodent nibbling on the wires.

"I had to replace some wiring due to rabbits chewing," a Times-Call reader said on Facebook.

"There is apparently an epidemic with squirrels and rabbits chewing electrical wiring and so forth under the hoods of cars," another called into the TC-Line on Jan. 4.

Not quite an epidemic, local mechanics say. But far from uncommon.

"It is a fact," said Scott Nichol of Hitek Professional Automobile Repair, who says he gets six or seven cases of rodent damage a year. "It is a cold, hard, nasty fact. Summertime, wintertime, fall, it doesn't matter. ... The more squirrels you have in an area, the more you see things like this."

Travis Paswaters of Hayes Automotive said he tends to see it a little more in the winter. Squirrels and mice aren't specifically looking for your wires, he said, they're looking for a place to nest -- and in the winter, a recently parked car that sits for a while provides a perfect home.

"We pull nests out of air boxes and intake valleys all the time," Paswaters said. "And if they get down and chew something you can't find, you can get a pretty nasty gremlin. One, I remember, chewed the ignition coil wires. The car would run rough because one of the cylinders wasn't firing."

And sometimes it can add up to more than just a rough ride. Last May, a car caught fire and burned; police later determined it was because of a squirrel nest in the engine.

"If they chew up the wiring, you can have a car-becue," Nichol said.

So what can a driver do?

First, keep the car in a garage if you can. You can't close off all the entryways a rodent would use -- they're openings that the car needs -- but putting the vehicle inside makes it less likely that squirrels will pay a visit. Mice may still be a risk, though, Nichol said, especially outside of town.

Second, open up the hood and check the engine regularly, Paswaters said. If you find twigs, bits of leaves or other nest-building material, you might just have a visitor. Having the oil changed regularly will help, too, he said, since the mechanic will be alert to signs of trouble.

One common home remedy is to use mothballs or paint the wires with Tabasco sauce to discourage chewing. That can work, Paswaters said, but it can also have unpleasant consequences, since the fresh air intake is near the core of the engine.

"It'll make the HVAC unpleasant," he said, referring to the passenger heating and cooling system. "You'll be getting that smell yourself."

Nichol advised not to try putting poison down near the car; the risk of a pet consuming it by mistake isn't worth it, he said. The best thing you can do, he said, is not to let the car sit.

"Don't keep it parked for weeks on end," he said. "Make sure the car moves."

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA 

Click image to enlarge

Mice love to gnaw. It is their nature. It is not because they have to our their teeth will grow into their brain, that is an old wives tale. They do it because it simulates things they see in nature. Wires are like blades of grass so they gnaw on it. Needless to saw this is very dangerous. They also gnaw on things to create opening & runways. If the population is high they may gnaw to relive built up stress like we bite our finger nails. They may also gnaw to gather nesting materials.

This gnaw hole was found in a basement of a home that had a severe mouse problem. The mice created this hole in the sheetrock & had several nests in the wall void. They also made runways in the walls to move from floor to floor. What is more disgusting is that if you look closely you can see the urine stains among all the fecal droppings. This picture is worth a thousand words! Certainly proof that mice are a real big issue in homes and businesses!

Jason Leduc
Service Supervisor

Pest Control, RI, Pest Control, MA